Physics Trigonometry? Advice, Please!!

Ooooh, what a week!! Many of you know this same fate, but when you register at a 4-year university as “non degree” seeking, you get to wait until the very last minute to register.

For me, that was Monday. I was watching my classes fill up left and right (and I only had 2 sections that would work for me, because of my job), but as luck would have it, I was able to register for both Organic Chemistry and Non-Calculus Physics successfully.

If the classes are half as hard as the process of getting into them was, I may be in for a long, hard semester!!!

The Physics Dept Chair had to waive my math pre-reqs (because the university would not have done it in time), and when she looked at my transcript she told me that I really wouldn’t be prepared for the Physics class. (The only math on my college transcript is business calculus and statistics.)

She kept saying over and over that I needed trigonometry. And she actually said the following: “I’ll let you in this class against my judgment…but you’re just not going to get A’s like you’re used to getting” (as she’s waving my transcript around wildly).

So…bull, meet red flag… that sounded like a challenge to me! (I’m a Type-A Taurus…I can’t help it!)

I bought “Trigonometry Demystified” and am trying to get through a good chunk of it before class starts–but I’m wondering if you guys can chime in on what parts of trigonometry I’m going to need to have a grasp on? I have to work smart, because I’m running out of time. In all honesty, it’s been 13 years since I’ve had any Trig (or calculus, for that matter), so it’s all buried. Any thoughts?

Luckily, this woman will not be my teacher. Good grief…

Carrie, don’t worry, your physics questions answered!

I’ve got physics demystified, it’s a good book. Here’s what you need and why.

Trig functions of Sin, Cos, Tan and how to use them. Use the acronym soh cah toa. Sin = opp/hyp. Etc.

You’ll use these to help with vectors (direction and magnitude). The rest is basically algebra. Seriously, no worries.

Practice, practice, and check out

You’ve got this!


Vectors, and triangles. Seriously, if you understand how to use the trigonometric frunctions to calculate angles and/or length of sides of triangles, that’s the biggest piece.

The review I did of trig (which was 30 years in my past) for physics was honestly relating trig functions to triangles (let’s see - the length of the opposite side over the adjacent side is ___. ) Vectors I remembered.



As others mentioned, focus on reviewing vectors and the basic soh cah toa triangle stuff. Vectors are not that hard, but it’s intimidating when the teacher starts talking about stuff you are supposed to know and everyone else seems like they do. Physics is quite unlike Bio and Chem because it is a learned skill like playing an instrument. I warn you that you can be easily fooled into thinking you have it because it makes sense in class. Then the first exam happens and you realize you can only do well by working lots and lots and lots of problems.

Organic is exactly halfway between physics and bio. There’s a bunch of rules, behaviors, and facts to commit to memory then you have to practice, practice, practice to acquire the skill of their correct application. Spend your time practicing problems and you won’t have to memorize much. There’s always some exception or little quirk about a particular reaction that you forgot about and you can only remember it all by practicing doing problems.

Don’t be discouraged because it is doable. I took Physics 2 and Organic 1 and the labs all together and worked full time and got A’s but I’d kind of rather not repeat that anytime soon. I took a 2-credit Intro to Physics class because I was in your boat (same age and math background) and that made Physics 1 quite easy. Physics 2 was harder.

Take the Physics Chairperson seriously because she knows the specific class material and professor you will be taking which is different from school to school. Keep your eye on the non-W drop date (usually a week or so) and make sure you feel you can get the grade you want.

You can do it! Keep that positive attitude and work your tail off from day 1.

Hi Carrie…when I started pre-med courses, I was 20 years from my last calculus class and 22 years from my last trig class. I took non-calc Physics and did not have trouble brushing up on trig while taking the class. You will have access to a lot of practice problems; doing those conscientiously will help you more than anything else.

But – two things –

For no particular reason, a year before I started pre-med, I did all the problems in Math Review for Standardized Tests. It’s a Cliffs Notes book by Jerry Bobrow. Very basic stuff but I found it a great help, especially with exponent rules and basic trig. I was really glad I had had that review.

Second, while studying for the MCAT, I had a freakout and bought Introductory Physics with Algebra as a Second Language (Loucks). I only skimmed it but it seemed great.

If you PM me your address I can mail you my copy. I didn’t write in it at all.


  • carrieliz Said:
She kept saying over and over that I needed trigonometry. And she actually said the following: "I'll let you in this class against my judgment...but you're just not going to get A's like you're used to getting" (as she's waving my transcript around wildly).

Just a point out of curiosity- how did you have calculus but not trigonometry? I never took a trig course, but that's because I learned it in the process of taking calc. Saying you won't pass a class because you have calculus but not trig sounds like saying it's a problem to have an A in a course's advanced version without having taken the course's intro version first.

More to the point, though- I like to think of trig as being geometry with a lot more abstract thinking and abstract mathematical constructs. If that sounds like the kind of thing you’re good at, I wouldn’t worry.

  • Fedaykin Said:
Just a point out of curiosity- how did you have calculus but not trigonometry?

Ha--I guess that was a little confusing! I had business calculus my freshman year of college, 15 years ago. In high school, I had all the Algebras, geometry, trigonometry, pre-calculus, and general calculus/diff-eq. So when I got to college, I took one semester of math and then left it behind as I decided on a behavioral psych degree. (other than a year of statistics...)

This particular department chair (who I was later told is actually quite looney) wanted to see some kind of trig experience on my transcript and was treating my 'business calc' class as a survey fluff course, even though it was actually quite thorough.

Ah, well... I'm not as worried about the trig anymore. Thanks to some great OPM advice, I've been brushing up and feel fairly confident. Now it's just on to the actual physics content! Whew!! Thanks for the encouragement!

This might just be my crazy way of thinking, but I thought the calc-based physics course was much easier than the trig-based because you can make your own equations as you need to . . . Would the dept. chair not consider letting you take the calc-based option?

College level algebra was a prereq for me. I bought a $20 book, studied it for ~30 hours then took the CLEP test to test out of it. That was adequate preparation for Northwestern’s physics and I’ve never taken math in college.

I’d recommend you do something similar if you have not started physics already and are concerned (don’t take the CLEP test though).

I think having rock solid algebra is a requirement to get an A in a tough physics class. If you study hard you can learn it during the course though if u have weak spots and extra time.